Having already established himself in the first team at St Andrew's, the 16-year-old is being heavily linked with a switch to the Blues, Manchester United or Borussia Dortmund.
However, despite the possibility of his former club winning the race for the prospect, Sinclair feels that the teenager would benefit from opting against a move to Stamford Bridge.
Speaking to GentingBet, Sinclair said: "He has to think about playing games, getting better and improving as a player – which I think will be very difficult for him to do at Chelsea.
"You look at the youngsters coming through the ranks at Chelsea and you'd say that there are better players coming through the academy than Bellingham anyway.
"So, if he is going to move on from Birmingham and kick on at a higher level, it is really important that he goes to a club where he can play week in, week out as that's the only way he'll improve and fulfil the potential that he's got. I think Bellingham needs to very wary of his next move."
Bellingham has contributed four goals and two assists from 32 outings in the Championship this season. body check tags ::